Antimicrobial Resistance of Campylobacter coli Isolated from Caecal Samples of Fattening Pigs at Slaughter

Relevant foodborne bacteria associated to pork production chain

Foodborne diseases affect millions of people globally, resulting in a huge number of hospitalizations and deaths. In this context, laboratory-based research is crucial to identify the major pathogens as well as the relevance of each one for distinct food production chains. Pork meat is very popular, being the most consumed meat in many countries and its inspection at the slaughterhouse is the main component of surveillance to protect consumers. Healthy pigs may carry pathogenic and antibiotic resistant bacteria that can be subsequently transferred to humans through the consumption of contaminated meat. Further, the food processing environment can harbor pathogenic persistent bacteria, representing a risk of cross-contamination to pork meat, demanding strict slaughtering procedures. Among these foodborne bacteria, Salmonella, Yersinia enterocolitica, Escherichia coli, Campylobacter spp., Listeria monocytogenes and Staphylococcus aureus are the most relevant in the pork production chain. Molecular subtyping has been fundamental for pathogen detection and also to track transmission, and nowadays it is a key component of the efforts to prevent and control foodborne diseases. In this chapter, characteristics of these major foodborne bacteria associated to pork meat will be addressed, including their occurrence and importance along the pork production chain, worldwide distribution, typing, as well as control and prevention measures from farm to fork.

Identification of Antimicrobial-Resistant Zoonotic Bacteria in Swine Production: Implications from the One Health Perspective

Antimicrobial resistance poses a major threat to global health and food security and is primarily driven by antimicrobial use in human and veterinary medicine. Understanding its epidemiology at farm level is crucial for effective control measures. Despite the significant reduction in antibiotic use in conventional livestock production, the swine sector traditionally has a higher level of antibiotic use in veterinary medicine. Consequently, multidrug resistance (MDR) among microbial isolates of swine origin has been relatively frequent. The aim of this study was to assess the presence of multidrug-resistant (MDR) bacteria, enteric pathogens and resistance genes to the main antibiotics used in clinical practice, both within the environment and in animals across pig farms characterized by varying degrees of sanitary status. A total of 274 samples were collected. Of these, 34 samples were collected from the environment (wall swabs, slat swabs and slurry pit), and 240 samples were collected from animals (sows' and piglets' rectal faeces). All samples were analysed for MDR bacteria and enteric pathogens. The study revealed a high frequency of extended-spectrum beta-lactamases (ESBL)-producing Enterobacterales and Campylobacter spp., with ESBL-producing Enterobacterales predominating in high health status farms (environment and animals) and Campylobacter spp. in both high health status and low health status environments. Additionally, a high percentage of methicillin-resistant Staphylococcus aureus (MRSA) was found, mainly in environmental samples from high health status farms, and Clostridioides difficile was distributed ubiquitously among farms and samples. Furthermore, though less frequently, vancomycin-resistant Enterococcus faecium (VRE) was isolated only in high health status farms, and Gram-negative bacilli resistant to carbapenems were isolated only in environmental samples of high health status and low health status farms. This study underscores the importance of surveillance for MDR bacteria in farm animals and their environment, including their waste. Such ecosystems serve as crucial reservoirs of bacteria, requiring national-level surveillance to promote responsible antibiotic use and pandemic control.

First study in the frequency of isolation and phenotypic antimicrobial resistance profiles of pig and cattle origin Campylobacter strains in Romania

Campylobacter spp. is recognized as one of the most common pathogens involved in the development of gastrointestinal infections in humans. The current study aimed to enhance the knowledge on the occurrence and molecular characterization of Campylobacter spp. in pigs and cattle origin caecum samples (n = 56) collected in one year, from nine Romanian slaughterhouses, and to determine the antimicrobial resistance profile of the isolated strains. All Campylobacter spp. strains (n = 41) isolated from swine and cattle caecum samples were analyzed in terms of antimicrobial resistance, in accordance with the EURL protocol and with the Commission Implementing Decision No. 2020/1729. The prevalence rate for C. coli. in pig caecum samples was 92.3% (36/39), and the prevalence of C. jejuni, in cattle origin samples was 29.4% (5/17). C. coli strains isolated from pigs proved resistant to tetracycline 75% (27/36), ciprofloxacin 69.4% (25/36), erythromycin 8.3% (3/36), ertapenem 2.8% (1/36) and gentamicin 2.8% (1/36), but no resistance was observed towards chloramphenicol. C. jejuni strains originating from cattle expressed resistance to ciprofloxacin 60.0% (3/5) and tetracycline 20.0% (1/5), but they were susceptible to chloramphenicol, erythromycin, ertapenem and gentamicin. In the present study, 19.5% (7/36) C. coli strains isolated from pigs were identified as multidrug-resistant (MDR) bacteria. The obtained results demonstrated that pigs especially, but cattle to, can be considered important natural reservoirs for zoonotic multidrug-resistant Campylobacter strains, having a stimulating effect for further studies aiming at the molecular screening of the genotypic antimicrobial resistance processing of a higher number of samples.